PROJECT SUMMARY Consumer products increasingly contain engineered nanomaterials (ENMs) or generate incidental nanoparticles (INPs). ENMs often improve the capabilities of a product, such as through the imbuement of added functionalities in 3D printing filaments or anti-staining ability in construction materials. Other products, such as cosmetic airbrushes and aerosol applicators, disburse small particulates by design which often reach the nanoscale (INPs). Studies continue to reveal adverse human health effects to exposure to ENMs and INPs, especially when airborne. Numerous tools and assays already exist which can accurately characterize the size, concentration, composition, and other properties of ENMs and INPs. While additional improvements to characterization equipment is certainly valuable- especially with regard to the discernment of carbonaceous ENMs from INPs- the greatest impact on human health can be realized through the development of a robust exposure assessment protocol using the equipment already available. We propose to develop an evaluation protocol for the independent assessment of exposure risk to airborne ENMs and INPs released by consumer products- the NanoSafe VerifiedTM protocol. Exposure evaluations will occur in NanoSafe?s Class 1000 cleanroom, where ENM and INP concentration and size distribution will be measured while also sampling released airborne and surface-deposited nanomaterial for compositional characterization using electron microscopy, mass spectroscopy, and Raman spectroscopy. In Phase I, three 3D printer models using seven ENM-containing filaments and three INP-generating cosmetic airbrushes using a variety of formulations will be assessed for exposure risk during operation. These assessments will guide Protocol development, while additional products will be tested in Phase II. In the ultimate commercial vision, NanoSafe will evaluate ENM-containing and INP-generating consumer products for user exposure risk to respirable particulates. Products demonstrating low ENM exposure risk by this NanoSafe VerifiedTM protocol will earn the use of the accompanying label, analogous to UL or NSF marks acquired on other products. This mark will encourage consumer purchase of safer ENM- containing and INP-generating products, and in turn, inspire manufacturers to develop consumer products that present lessened ENM and INP exposure risk.